- The General Circulation Research Section/Laboratory
- The Geophysical Fluid Dynamics Laboratory
- Syukuro Manabe and the GFDL General Circulation Modeling Program
- The GFDL Atmospheric GCMs
- Current GFDL Models
- Links to Related Sites
- References

The Geophysical Fluid Dynamics Laboratory, located at Princeton University, is among the oldest institutions to have developed general circulation models. Its origins and current work are described below.

In 1955, at von Neumann's instigation, the U.S.
Weather Bureau created a General Circulation Research Section under
the direction of Joseph Smagorinsky. Smagorinsky felt that his charge
was to continue with the final step of the von Neumann/Charney
computer modeling program: a three-dimensional, global,
primitive-equation general circulation model of the
atmosphere.[1]
The General Circulation Research Section was initially located in
Suitland, Maryland, near the Weather Bureau's JNWP unit). The lab's
name was changed in 1959 to the General Circulation Research
Laboratory, and it moved to Washington, D.C.

In 1955-56, Smagorinsky collaborated with von Neumann, Charney, and
Phillips to develop a 2-level, zonal hemispheric model using a subset
of the primitive equations.[3]
Beginning in 1959, he proceeded to develop a nine-level
primitive-equation GCM (still hemispheric).[4]
Smagorinsky was among the first to recognize the need to couple ocean
models to atmospheric GCMs; he brought the ocean modeler Kirk Bryan
to the GCRL in 1961 to begin this research.

The General Circulation Research Laboratory was renamed the Geophysical Fluid Dynamics Laboratory in 1963. In 1968, the GFDL moved to its current home at Princeton University.

In 1959, Smagorinsky invited Syukuro Manabe of
the Tokyo NWP Group to join the General Circulation Research
Laboratory, where he assigned Manabe to the GCM coding and
development. By 1963, Smagorinsky, Manabe, and their collaborators
had completed a nine-level, hemispheric primitive-equation GCM.^{
}Manabe was given a large programming staff. He was thus able to
focus on mathematical structure of the models, without becoming
overly involved in coding. (Leith, by contrast, worked mostly alone,
and wrote his own code.)

In the mid-1960s, as Smagorinsky became increasingly involved in planning for the Global Atmospheric Research Program (GARP), Manabe became the de facto leader of GFDL's GCM effort, although Smagorinsky remained peripherally involved. Until his retirement in 1998, Manabe led one of the most vigorous and longest-lasting GCM development programs in the world.

Manabe's work style has been highly collaborative. With his colleagues Strickler, Wetherald, Holloway, Stouffer, and Bryan, as well as others, Manabe was among the first to perform carbon-dioxide doubling experiments with GCMs,[5] to couple atmospheric GCMs with ocean models,[6] and to perform very long runs of GCMs under carbon-dioxide doubling.[7] Another characteristic of Manabe's work style is a focus on basic issues rather than on fine-tuning of model parameterizations.

The names used in the following section are the informal terms used by GFDL members, who do not always agree on their interpretation.

## MARKFORT

The MARKFORT series began with Smagorinsky's nine-level, 3-D hemispheric model, and was used well into the 1960s. Initially, the model was run on the IBM STRETCH. A number of GFDL's most influential publications resulted from the MARKFORT model.[8]

## Zodiac

The Zodiac model series was the second major GFDL GCM. It was a finite-difference model. The chief innovation was the use of a new spherical coordinate system developed by Yoshio Kurihara.[9] This model remained in use throughout the 1970s.

## Sector

The Sector series was not an independent GCM, but a subset of the GFDL global models. To conserve computer time (especially for coupled ocean-atmosphere modeling), integrations were performed on a 60-degree longitudinal "slice" of the globe, with a symmetry assumption for conversion to global results. In the early sector models, highly idealized land-ocean distributions were employed.[10]

## Skyhigh

Work on Skyhigh, a high-vertical-resolution GCM covering the troposphere, stratosphere, and mesophere, began in 1975.[11]

## GFDL Spectral Model

In the mid-1970s, GFDL imported a copy of the spectral GCM code developed by W. Bourke at the Australian Numerical Meteorological Research Centre.[12] Interestingly, Bourke and Barrie Hunt had originally worked out the spectral modeling techniques while visiting GFDL in the early 1970s.

## Supersource

Beginning in the late 1970s, Holloway began to recode the GFDL spectral model to add modularity and user-specifiable options. The result was Supersource, the modular, spectral atmospheric GCM that remains in use at GFDL today. "Holloway fit the physics from Manabe's grid model (ZODIAC and relatives) into the spectral model. Holloway then unified all the versions of this new spectral model into one Supersource."[13]

Users can specify code components and options. Among these options is a mixed-layer ocean model, but Supersource does not contain an ocean GCM. Supersource code has frequently been used as the atmospheric component in coupled OAGCM studies.[14]

GFDL Home Page

References

[1]
J. Smagorinsky, "The Beginnings of Numerical Weather Prediction and
General Circulation Modeling: Early Recollections," *Advances in
Geophysics* 25 (1983): 3-37.

[3]
J. Smagorinsky, "On the Numerical Integration of the Primitive
Equations of Motion for Baroclinic Flow in a Closed Region,"
*Monthly Weather Review* 86, no. 12 (1958): 457-466.

[4]
J. Smagorinsky, "General Circulation Experiments with the Primitive
Equations," *Monthly Weather Review* 91, no. 3 (1963):
99-164.

[5]
S. Manabe, "The Dependence of Atmospheric Temperature on the
Concentration of Carbon Dioxide," in *Global Effects of
Environmental Pollution*, ed. S.F. Singer (Dallas, Texas: 1970),
25-29.

S. Manabe, "Estimates of Future Change of Climate Due to the Increase
of Carbon Dioxide," in *Man's Impact on the Climate*, eds. W.H.
Mathews, W.W. Kellog, and G.D. Robinson (Cambridge, Mass.: MIT Press,
1971), 250-264.

[6]
S. Manabe and K. Bryan, "Climate Calculations with a Combined
Ocean-Atmosphere Model," *Journal of the Atmospheric Sciences*
26, no. July (1969): 786-789.

[7]
S. Manabe and R.J. Stouffer, "Multiple-Century Response of a Coupled
Ocean-Atmosphere Model to an Increase of Atmospheric Carbon Dioxide,"
*Journal of Climate* 7, no. January (1994): 5-23.

[8]
S. Manabe, J. Smagorinsky, and R.F. Strickler, "Simulated Climatology
of General Circulation with a Hydrologic Cycle," *Monthly Weather
Review* 93, no. December (1965): 769-798.

S. Manabe and R. Wetherald, "Thermal Equilibrium of the Atmosphere
with a Given Distribution of Relative Humidity," *Journal of the
Atmospheric Sciences* 24 (1967): 241-259.

J. Smagorinsky, S. Manabe, and J.L. Holloway, "Numerical Results from
a Nine-Level General Circulation Model of the Atmosphere," *Monthly
Weather Review* 93 (1965): 727-768.

[9]
Y. Kurihara, "Numerical Integration of the Primitive Equations on a
Spherical Grid," *Monthly Weather Review* XCIII, no. 7 (1965):
399-415.

[10]
S. Manabe, K. Byran, and M.J. Spelman, "A Global Ocean-Atmosphere
Climate Model: Part I. The Atmospheric Circulation," *Journal of
Physical Oceanography* 5, no. 1 (1975): 3-29.

[11]
J.D. Mahlman, R.W. Sinclair, and M.D. Schwarzkopf, "Simulated
Response of the Atmospheric Circulation to a Large Ozone Reduction"
(Proceedings of the WMO Symposium on the Geophysical Aspects and
Consequences of Changes in the Composition of the Stratosphere, 26-30
June 1978, Toronto, Canada), 219-220.

[12]
T. Gordon and B. Stern, "Spectral Modeling at GFDL" (GARP Programme
on Numerical Experimentation, 1974).

W. Bourke, "A Multi-Level Spectral Model. I. Formulation and
Hemispheric Integrations," *Monthly Weather Review* 102 (1974):
687-701.

C.T. Gordon, "Verification of the GFDL Spectral Model," in *Weather
Forecasting and Weather Forecasts: Models, Systems, and Users. Notes
from a colloquium, Summer 1976*, eds. D.L. Williamson et al.
(Boulder, CO: National Center for Atmospheric Research, 1976), v.
2.

[13]
R. Stouffer to P. N. Edwards, personal communication, 5/13/98.

[14]
S. Manabe and R.J. Stouffer, "Two Stable Equilibria of a Coupled
Ocean-Atmosphere Model," *Journal of Climate* 1 (1988):
841-865.

S. Manabe and R.J. Stouffer, "Multiple-Century Response of a Coupled
Ocean-Atmosphere Model to an Increase of Atmospheric Carbon Dioxide,"
*Journal of Climate* 7 (1994): 5-23.